Thank You Page
Reference: Form Mail tutorial
Thank you for your competition entry. In the highly unlikely event that you have won a big prize, we will contact you.
Thank you for your subscription request. Expect (not!) our first newsletter within a few days.
On your Thankyou page, put whatever text is appropriate for your particular purpose. You may decide to have a separate Thankyou page for each particular kind of request. If so, give each page a different name, and change the PHP scripts (the line starting "header") to use the appropriate Thankyou page.